Maybe this will help:
PHP Code:
PerformFade(client, duration, const color[4])
{
new Handle:hFadeClient=StartMessageOne("Fade", client);
BfWriteShort(hFadeClient, duration);
BfWriteShort(hFadeClient, 2);
BfWriteShort(hFadeClient, (FFADE_PURGE|FFADE_IN));
BfWriteByte(hFadeClient, color[0]);
BfWriteByte(hFadeClient, color[1]);
BfWriteByte(hFadeClient, color[2]);
BfWriteByte(hFadeClient, color[3]);
EndMessage();
}